Rapid selection of viable transplantable human fetal pancreatic islets by trypan blue exclusion.

A rapid method of separating viable from nonviable human fetal pancreatic islets prior to transplantation is needed to quantify grafted tissue and optimize the possibility of successful treatment of diabetes mellitus in the recipient. After incubation with 0.04% trypan blue in isotonic Krebs-Ringer buffer solution for 15 min, the percentage of islets that excluded trypan blue was found to correlate well with fractional stimulated insulin secretion rates. The incubation procedure did not alter the subsequent insulin secretory capacity of the islets. Trypan blue exclusion rapidly and reliably identifies viable functional islet tissue prior to transplantation.